Large Scale Wi-Fi tracking using a Botnet of Wireless Routers

Wi-Fi tracking is a method relying on signals emitted by portable devices to track individuals for commercial, security or surveillance purposes. Wi-Fi tracking has the potential to passively track a large fraction of the population [12] and is therefore an ideal population surveillance technology and a serious privacy threat. We argue that Wi-Fi routers make an ideal building block to create a large scale Wi-Fi tracking system. This paper first presents the interesting features of Wi-Fi routers for tracking and describes how they can be easily turned into Wi-Fi tracking devices through software modification. We then introduce the concept of a large scale Wi-Fi tracking system based on routers and we propose a design for such a system, including stealth communications and deployment. Finally we provide a first evaluation of the tracking capabilities of an hypothetical Wi-Fi tracking system through a set of simulations based on real-world datasets. Results show that the spatial distribution of Wi-Fi routers is such that compromising even a small fraction of Wi-Fi routers is sufficient to track people for a large fraction of the time.